Phalaenopsis Orchid has yellow buds. Why?

[D O'Conner]

I recently bought a new orchid, since i have had it, 2 new buds have opened, and i now have 4 total. the orchid has one spike, and their is a branch trying to start on the spike. About a week ago one of the buds turned yellow, so i was worried that it might have had a disease, and plucked it off. now the first bud on the new branch has turned yellow, in like a day, it was green. Is that just a part of its process, or is something wrong? i'm not going to pluck this one, and just see what happens, but all the websites i have found don't say anything about a yellow bud. It's not a weird yellow, it's one color, not browning or anything just turned yellow. the flowers are yellow, could that be it? but the buds that opened looked more green to me.. please help if you know about orchids.....